This invention relates to nitrous oxide fuel systems for internal combustion engines, and, more particularly, to a nitrous module construction that improves the distribution of the nitrous oxide/fuel mixture amongst the cylinders of the internal combustion engine.
In a conventionally fueled internal combustion engine, vaporized fuel, typically either gasoline or alcohol, introduced through a carburetor mixes with outside air drawn into the engine manifold to form a combustible mix. That combustible mix, as example, is drawn through an intake runner of the manifold and into a cylinder of the engine where the combustible mix is ignited, typically, by the spark produced by a spark plug in the engine ignition system. The resultant explosion in the engine cylinder drives the piston, producing the mechanical force that is ultimately transferred to the wheels of the automobile. The foregoing combustion process repeats for each cylinder in the engine. The proportion of oxygen in a given volume of air relative to the other components of the air, such as nitrogen, is relatively fixed. Typically, through proper carbureation, the ratio of oxygen and fuel in the mixture is set to the optimal ratio that is known to achieve the most efficient explosion.
To enhance performance of internal combustion engines in automotive racing application beyond that possible with conventional fuel systems, drag racing enthusiasts learned to inject nitrous oxide (xe2x80x9cN2Oxe2x80x9d) into the cylinders along with the combustible mix introduced by the carburetor and to accompany the nitrous injection with an injection of additional fuel, the gasoline or alcohol used as fuel in the carburetor. Air typically contains about 15% oxygen (by volume) while Nitrous Oxide contains 33% oxygen. When heated to elevated temperatures available within the engine, the nitrous oxide decomposes into molecules of nitrogen and oxygen. In that way oxygen is released and added to that oxygen in the air introduced through the carburetor, enriching the combustible mix in the cylinders. To a limit, the greater the percentage of oxygen in the combustible mixture, the stronger is the explosion that results when the mixture is ignited. Therefore, when nitrous oxide is injected into the combustion chamber of the cylinder, the power of the explosion is greatly increased, thus producing increased horsepower from the engine. The additional fuel accompanying the nitrous oxide prevents the combustible mixture from becoming too lean as could cause overheating and damage to the engine. As an advantage, a nitrous oxide system may be used without requiring expensive modification of the internal combustion engine
Two principal techniques for introducing the nitrous oxide are currently in use, one by injection of the nitrous directly into the intake runners. The other by injecting the nitrous into the plenum of the intake manifold.
The first, often referred to as a nitrous nozzle system, employs multiple nozzles, each containing a pair of outlets for individually expressing both nitrous oxide and fuel. Each nozzle is placed directly into a respective one of the intake runners. When the system is activated during engine operation, nitrous oxide and fuel are introduced into a respective runner by the nozzle associated with that runner. The nitrous is under high pressure and, on expression from the nozzle, changes from a liquid state to what is said to be a predominantly gaseous state. That essentially vaporized nitrous oxide impacts the expressed fuel at high velocity. The force of that impact atomizes the fuel and the nitrous oxide mixes therewith. That nitrous and fuel mixture merges into the air/fuel mixture being drawn through the carburetor into the intake runner through which the combustible mixture is drawn into respective engine cylinders. The nozzle system is considered the optimal technique for delivering nitrous oxide to the engine. A leading nozzle design, as example, is presented in U.S. Pat. No. 5,699,766, granted Dec. 23, 1997 to Wood et al., entitled Nozzle for Mixing Oxidizer With Fuel.
The second technique is referred to as a nitrous module or, as variously termed, nitrous plate system. The module or plate employs a generally rectangular or square metal plate that contains a central opening or passage sized to match the plenum of the intake manifold and at least one pair of spray conduits that extend across that central passage to respectively introduce the nitrous oxide and fuel into the plenum of the intake manifold. That plate is sandwiched between the carburetor and the intake manifold of the engine. Nitrous oxide and fuel are respectively applied through respective passages in the plate and into the ends of the respective spray conduits, where the respective fluids are expressed through the jets or small holes in the side of the conduits into the central opening to merge with the air/fuel mixture being drawn through the carburetor. A leading design for a nitrous plate system is described in U.S. Pat. No. 5,839,418 to Grant entitled Dual Stage Nitrous Oxide and Fuel Injection Plate, granted Nov. 24, 1998 (the xe2x80x9c""418 Grant patentxe2x80x9d).
In the design described in the ""418 Grant patent a module, the plate member contains the central opening that serves as a passageway for the air and fuel stream to flow from the carburetor into the intake manifold. The plate also supports two pairs of adjacent straight parallel spray conduits with one pair of conduits overlying and criss-crossing the other pair of conduits, referred to as a double stage system. One spray conduit in each pair, located downstream, contains outlets, referred to as nozzles, for spraying fuel. The other conduit of the pair, located upstream, contains outlets for spraying nitrous oxide in a generally downstream direction. One pair of nitrous and fuel conduits extend across the passage with the ends anchored in opposed sidewalls on the plate that border the passageway. The other pair of nitrous oxide and fuel conduits are oriented perpendicular to the first pair and are similarly anchored in another set of opposed sidewalls of the plate. Fuel and nitrous oxide are fed into respective internal conduits in the plate and connect to an end of the respective fuel and nitrous oxide spray conduits in each of the two pairs of conduits.
Historically, the nozzle system attained superior results over predecessor techniques, including over the nitrous plate system. As a result, the nozzle system achieved wide acceptance among racing enthusiasts. An unfortunate problem is faced by that system, however, one that is political in nature. The nozzle system is not permitted by the racing associations for use in several classes of drag racing. That prohibition limits many drag racers to use of the plate system.
However, the plate system is not without a drawback. Distribution, that is, the even or balanced distribution of the added nitrous oxide and fuel amongst all of the engine cylinders is a key factor in the use of the plate system. The plates are known to have problems with distribution; they do not always evenly distribute the nitrous oxide and fuel amongst the many intake runners of the manifold. As a consequence, some cylinders of the engine receive more or less of the combustible mix than other cylinders; and that imbalance not only detracts from engine performance, but could potentially harm the engine internally. Existing nitrous plates currently being marketed are found to have poor or inconsistent distribution leading to inconsistent quantities of nitrous oxide and fuel reaching the engine cylinders, something that drag racers tend to steer away from. As an advantage, the present invention avoids that problem.
The spray conduits of the prior design each span the length of the central passage through the plate. When the respective solenoid valves in the automobile open to permit the nitrous and fuel to enter the respective spray conduits, the respective liquids flow into and to the end of the conduits. Although the nitrous is under a very high pressure Some very small but finite interval of time is required for the initial flow of the nitrous oxide to reach the end of the conduit so that the respective spray conduits fully function to express nitrous oxide evenly from all outlets in the conduit. Accordingly, some lag will exist in developing the horsepower available from the engine through use of the plate system. The means for reducing that lag in a plate system has not been known. As an advantage, the present invention reduces that lag.
The consequences of the initial flow of nitrous oxide into the spray conduit has also been thought to be a possible source of some of the distribution problem experienced by users of the prior nitrous plate system. It has been asserted that nitrous oxide under high pressure is capable of vaporizing from the fluid state in the short time that it takes for the initial flow of nitrous oxide to span the distance from the center of the plate passage way over to the end of the conduit at the distant side wall of the passage way. Since the size and shape of the passage way is fixed to the size of the carburetor throat and the intake manifold passage, the reduction of that distance did not appear possible. As a further advantage, the present invention reduces the distance the fluids must travel to reach the end of the respective conduits.
Therefore, a principal object of the invention is to improve the distribution of nitrous oxide and fuel in nitrous plate systems and improve the horsepower developed by an engine that employs a nitrous plate system.
An additional object of the invention is to minimize or entirely prevent premature vaporization of any part of the nitrous oxide inside the nitrous oxide spray conduit of the nitrous plate.
A related object of the invention is to reduce start up lag in a nitrous plate system and, thereby, enhance acceleration of the engine.
And, it is an additional object of the invention to increase the nitrous oxide/fuel handling capability of a plate system, permitting the plate to deliver greater volumes of nitrous oxide and fuel to the intake manifold so that greater horsepower may developed by the engine.
Briefly described, the present invention comprises a single stage nitrous oxide and fuel supply module, referred to in the industry as a plate, that is placed between the carburetor and the intake manifold of an internal combustion engine. The plate has a transversely extending passage or hole, referred to as an open core, which permits the fuel and air from the carburetor to pass through the plate and enter the plenum of the intake manifold of the engine (and pass therefrom ultimately into the combustion chamber of the respective engine pistons). The plate also contains eight spray conduits to respectively carry nitrous and fuel into the open core and distribute the respective contents into the plenum of the intake manifold.
The plate includes four nitrous oxide passages and four nitrous oxide inlets. Each of those inlets is associated with a respective one of the nitrous oxide passages for inputting nitrous oxide therein and four nitrous oxide spray conduits, positioned in the central passage in coplanar relationship. An end of each nitrous oxide conduit is supported from a plate wall and is open to admit nitrous oxide from a respective one of the nitrous oxide passages in the plate. The other end of each conduit, located near the center of the central passage is closed. Two of the nitrous oxide spray conduits are oriented along a first axis across the central passage with the distal ends thereof in a confronting relationship. The remaining two spray nitrous oxide spray conduits are oriented along a second axis across the passage with the distal ends thereof also in a confronting relationship, and the latter common axis across the passageway is perpendicular to the other common axis. As an additional aspect to the invention the distal ends of the spray conduits are mechanically linked together.
Four fuel spray conduits are included in the plate positioned coplanar in a separate plane underlying the former plane for the nitrous oxide spray conduits. A like arrangement to that of the nitrous oxide conduits is included for the plate and for the fuel spray conduits. The separate conduits, are individually supplied with respective nitrous oxide or fuel, functioning as separate entities.
As an advantage, the present invention employs twice the number of nitrous oxide and fuel inlets (e.g. fittings) than in conventional plates, and is able to supply twice the nitrous and fuel than any other plate of this type being marketed.
As a further advantage, the present invention ensures that an equal amount of nitrous and fuel is distributed to each quarter of the intake manifold, leading to a much safer and consistent increase in horsepower.
The foregoing and additional objects and advantages of the invention, together with the structure characteristic thereof, which were only briefly summarized in the foregoing passages, will become more apparent to those skilled in the art upon reading the detailed description of a preferred embodiment of the invention, which follows in this specification, taken together with the illustrations thereof presented in the accompanying drawings.